Telephone-exchange system



(No Model.)

W. R. COLE. TELEPHONE EXCHANGE SYSTEM.

No. 591,127. Patented Oct. 5,1897.

Wifneaa & 7711 6/1/01: mam/n f2. ca/c NITED STATES PAT NT FFICE;

WILLIAM R. COLE, O F DETROIT, MICHIGAN.

TELEPHONE-EXCHANGE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 591,127, dated October 5, 1897.

Application filed April 28, 1897 To all whom it may concern: V

Be it known that I, WILLIAM R. COLE, a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a specification, reference being had therein to the accompanying drawing.

My invention relates more particularly to telephone systems of that class commonly called group systems, in which the termi nal contacts of the outgoing or main lines are arranged in groups, connection being made between the different groups through internal or trunk lines corresponding in number to the main line and extending to all of said groups, at each of which theyare provided with a set of contacts, any of which may be connectedwith any of the contacts of the main line.

It is the object of my invention to obtain a system both simple in construction and one in which the connection may be quickly made by the operations of those different groups without danger of interference with each other or the necessity of more than one operator answering a call.

The invention consists in the peculiar construction, arrangement, and combination of parts, as more fullyhereinafter described.

In the drawing I show in diagram my exchange system as arranged for a complete metallic circuit; but I do not wish'to be limited to this precise construction, as it may be also used with single line-wires and ground circuit. a

A and A are two of the outgoing or main lines, which have their terminal contacts 0 G in different groups, and B and B are the cor responding trunk-lines, which extend to the different groups and are provided at each with terminal contacts. For the sake of simplicity in the drawings I have shown but these two groups with a single main line of each and its corresponding trunk-lines. Any number of groups may, however, be used, each having as many main lines as canbe conveniently attended to by a single operator.

D D are annunciators for the lines A A, respectively, and E E are auxiliary annun circuit in which it is included.

SerialNo. 634,207. (No model.)

ciators for the corresponding trunk-lines B B.

Each of the annunciators D D is arranged to each other that the operation of the main annunciator will also releasethe drop of the auxiliary annunciator, the movement of the latter opening a break in the branch 19 of the In the com struction shown in the drawings this is accomplished by providing each annunciator with a hook-arm c, secured to the armature d of an electromagnet d and adapted to hold the drop e in its normal position, the armature of the main annunciator being also pro vided with an arm f, extendi-nginto proximity to the armature of the auxiliary annunciator.

g is a movable contact carried by the drop e, and h is a stationary contact with which the contact 9 engages when the drop is in its normal position, said contacts constituting the terminals of a normally-closed break in the branch circuit 19, all so arranged that the movement of either armature will release its corresponding drop, and the operation of the main annunciator will also operate the armature of the auxiliary annunciator through the arm f, while the dropping of said auxi1-' iary annunciator will open a break in its circuit.

G are couplers or double plug-connecting conductors, of which there are a number arranged at each group, the drawing showing but one at each.

H are the operators telephone instruments, and I I are the electric generators for signalin Ihe cords Gare provided at one end with plugs J, adapted to engage with the contacts K of the trunk-lines, and at their opposite ends with plugs L, adapted to engage with the contacts O O of the main line. Where, as is shown in the drawing, the system is arranged for complete metallic circuits,.these plugs J and L are provided with double contacts adapted to engage with double spring-sockets forming the contacts K and O O. The inner contact of the plug L is also provided with a notch or shoulderj, adapted to engage with a projection 76 on one of the socket-contacts Z, and an inwardly-projecting pin on of insulating material.

with the contact Z, but adapted to be forced out of contact therewith by the insulatingf pin m when the plug is pressed far enough into the socket.

0 is another contact against which the con- The contacts Z and 02 form a normally closed short break in the connection a, while the contacts n and 0 form a normally open break ina branch P between the shunt a and a common line M running to all the groups.

N is a socket-contact connected to the operators instrument, with which the plugs J are adapted to engage, and O are plugs also connected to said instrument, adapted to engage with socket-contacts P, connected to the cords or conductors G.

Q are cords or flexible conductors connected to the lines F, one at each group and including the battery R and sounder S, the free end of the cord having the plug T.

U are connections between one conductor of each of the cords G and the line M, each of said connections containing a battery V and key V, normally opened.

In practice the operation of the exchange system is as follows: The operator of each group always keeps one of the cords G with its plug J placed in the socket N, thus con- ,necting it to the instrument H, as shown in dotted lines at X in the drawing. Supposing that one of the subscribers, such as on line A, should call up the central, the signalcurrent passing over the line and through the shunt a releases the main drop, and through the connection described also releases the auxiliarydrop. The operator then places the plug L of the conductor G, already connected at its opposite end to the instrument H, into the socket O, pressing it into said socket until the projection it enters the notch and then ascertains what other line the caller desires to be connected with. Again, supposing that the number wanted is that of line A, the operator takes the plug T, at-

, tached to the flexible connection Q, and

v corresponding to the line A.

touches the contact K of the trunk-lines B If the line A is not in use, this will complete an electric circuit through the conductor a; of the trunkline B, the connection 1) including the auxiliary annunciator E, the return-line F, battery R, and sounder S, thus releasing the drop of said annunciator and operating the sounder S. Should', however, line A be in use and its annunciator in its dropped position, the circuit cannot be completed by reason of break in connection I), caused by the withdrawal of contact 9 from contact h, and

the operator is made aware of this fact by the silence of sounder S. The operator finding line A not in use withdraws the plug J from the socket N, placing it in the socket K of trunk-line B, and also withdraws the plug L from socket O and places it into the socketY of the signal-generator I, as shown in dotted n is a spring-contact normally in contact lines at Z. In the meantime operator No. 2 of the group-line A has been informedby the dropping of latch E that some one desires to be connected to line A, and accordingly connects the contacts K and O by means of one of the connections G, but in placing the plug L in the socket 0 it is pressed in beyond the point where the tongue 7c engages with the notch j, forcing the insulating-pin m against the spring-contact n, breaking the contact of the latter with the contact l and pressing it into contact with v the contact 0, This, as before stated, will break the shunt a and close the connection with the line M. Operator No. 1 next operates the signal-generator l, which rings the bell of line A, after which the plug L is removed from the socket Y and replaced in the socket O, with the tongue is engaging with the notch j, and the drop of the main annunciator is reset in its normal position, thus including the lines A A in one complete meuse, it is only necessary to place the plug 0 into the socket P, which connects the instrument 1-1 in shunt with the line.

All interference or breaking in of other operators is prevented by the breaks in the connections Z), caused by the drops of the auxiliary annunciator remaining down all of the time the lines are in use. When the persons using these lines have finished, the ringing oif of either one will again drop the annunciator D. Operator No. 1 then presses the key W, which closes an electric circuit through the connections U and G, the conductor 00 of the trunk-line B, the conductor 3 of the connection G, the contact Z to the line A, the shunt a to the closed contacts n and 0, through the branch P to the line M, and through the battery V to the key W. This will drop the main annunciator D, which is the signal to the operator No. 2 that the lines are no longer in use, who therefore withdraws the plugs J and L of the connection G and resets the annunciator-drops D and E. In the meantime operator No. 1 has withdrawn the plugs J and L of connection spective main-line groups, said mainannunciators adapted in their operation to operate their auxiliary annunciators, and said auxiliary annunciators adapted vwhen operated to break their operating electric circuits, means at each group for closing an electric circuit through any one of the trunk-lines and .its auxiliary annunciator when the latter is in its normal position, a signal for indicating to the operator when said circuit is closed, and means for connecting any of the main-line contacts of each group with any of the trunkline contacts.

2. The combination with the main lines having terminal contacts arranged in groups, and trunk-lines adapted to form connections between the main lines of different groups, of main and auxiliary annunciators for each of said main lines and its corresponding trunklines, arranged at their respective main-line groups, each main annunciator being in shunt with its line and adapted in its operation to also operate its auxiliary annunciator and each auxiliary annunciator being adapted when operated to break its own circuit, means at each of the groups for operating any of said auxiliary annunciators when in nor mal position by closing an electric circuit through their corresponding trunk-lines, and means for indicating to the operator when said circuit is closed. v V 3. The combination with the main lines having terminals therefor arranged in groups and trunk-lines equal in number to the total number of main lines extending to all the groups and adapted to form intermediate connections between the different main lines, of an annunciator for each of the main lines arranged in a shunt therewith, auxiliary annunciators for each of the trunk-lines arranged in proximity to their corresponding main annunciators and adapted to be operated upon the operation of the latter, the line F extended to each of the groups, a connection between each of the trunk-lines and the line F including the corresponding auxiliary annunciator and a normally-closed break adapted to be opened upon the operation of the auxiliary annunciator, and a connection including an electric generator and a signal adapted to complete the circuit between said lines F and each of the trunk-lines and to indicate when the electric circuit is closed.

4. The combination with the main lines having terminal contacts arranged in groups, a trunk-line extending between said groups and connections adapted to couple main lines of different groups through said trunk-line, of an annunciator for each main line arranged in a shunt between it and the return main circuit, the line M extending to each group, means for breaking the connection of said annunciator with the return-circuit and connecting it to the line M, and means at each group for connecting said trunk-line and line M to complete an electric circuit through said annunciator. V

5. The combination with main lines having their terminal contacts arranged in groups, a trunk-line extending to the different groups, annunciators for each of the main lines and coupler connections for coupling main lines of different groups through said trunk-lines, of the line M, a connection for each main line including its annunciator and having a normally-opened branch connection to the line M and a normally-closed connection to the main-line return-circuit, an electric generator at each group adapted to be coupled between the lineM and said trunk-line, and a switch for breaking said closed main-line connection and closing said branch connection adapted to be operated by the coupling of said main and trunk lines.

6. In atelephone-exchange system the combination with the main lines having. their terminal contacts arranged in groups with an annunciator for each line, of a test and notification system comprising auxiliary annunciators corresponding to said main annunciator, each adapted to be operated from each of the groups and to be automatically operatcd by the operation of its corresponding main annunciator, and means for ascertaining from each of the groups whether said auxiliary annunciator is in use.

In testimony whereof I affix my signature in presence of two witnesses.

WVILLIAM R. COLE.

Witnesses:

M. B. ODOGHERTY, Orro F. BARTI-IEL. 

